Technologies for deodorization, sterilization, and toxic gas decomposition based on a plasma developed by high-voltage pulse discharges have recently been put to use. To generate such a plasma, a high-voltage pulse generating circuit capable of supplying pulses of an extremely short duration and a high voltage is required.
There has heretofore been proposed a high-voltage pulse generating circuit as disclosed in Patent Document 1, for example. As shown in FIG. 7, the proposed high-voltage pulse generating circuit 200 has a simple circuit arrangement including an inductor 204, a first semiconductor switch 206, and a second semiconductor switch 208 which are connected in series across a DC power supply unit 202. The first semiconductor switch 206 has an anode connected to an end of the inductor 204, whose other end is connected to the cathode of a diode 210. The diode 210 has an anode connected to the gate terminal of the first semiconductor switch 206.
When the second semiconductor switch 208 is turned on, the first semiconductor switch 206 is rendered conductive, applying the voltage from the DC power supply unit 202 to the inductor 204, storing induced energy in the inductor 204. When the second semiconductor switch 208 is thereafter turned off, since the first semiconductor switch 206 is quickly turned off, developing a sharply rising extremely narrow high-voltage pulse Po across the inductor 204. Therefore, a high-voltage pulse Po appears between output terminals 212, 214 of the inductor 204.
The high-voltage pulse generating circuit 200 is of a simple circuit arrangement which is capable of supplying the high-voltage pulse Po which has a sharp rising time and an extremely short pulse duration without the need for a plurality of semiconductor switches to which a high voltage is applied.
Patent Document 1: Japanese Laid-Open Patent Publication No. 2004-72994